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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2016-11-14 12:26:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-11-16 10:57:26 +0100
commit5fe86674840c6773d09943a78a5f7f3bf2420ffd (patch)
treef0c2894bde0779a6eedd30802bb2aed8652a3a13 /drivers/tty
parent7d4e00c6253bc57b1ac0764ca76d4a8642354b54 (diff)
downloadlinux-5fe86674840c6773d09943a78a5f7f3bf2420ffd.tar.bz2
serial: 8250_dma: power off device after TX is done
When any 8250 based driver sets up DMA and has UART_CAP_RPM capability enabled the device is left powered on after transfer is done. We need to schedule a device suspend operation when DMA completes the transfer. The patch is based on the work done by the reporter. Reported-by: Huiquan Zhong <huiquan.zhong@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/8250/8250_dma.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index fdbddbc6375d..26f17456b0d7 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -72,10 +72,15 @@ int serial8250_tx_dma(struct uart_8250_port *p)
struct dma_async_tx_descriptor *desc;
int ret;
- if (uart_tx_stopped(&p->port) || dma->tx_running ||
- uart_circ_empty(xmit))
+ if (dma->tx_running)
return 0;
+ if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) {
+ /* We have been called from __dma_tx_complete() */
+ serial8250_rpm_put_tx(p);
+ return 0;
+ }
+
dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
desc = dmaengine_prep_slave_single(dma->txchan,